Lamp



Dec. 2, 1930 c. A. B; HALVORSON LAMP Filed Nov. 17', 1928 Inventor": Cr-omwel| A. BHalvorson by M His Armor-neg- Patented Dec. 2, 1930 UNITED STATES PATENT OFFICE CROMWELL A B. HALVORSON, OF LYNN, MASSACHUSETTS, ASSIGNOR T GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK LAMP Application fil ed November 17, 1928. Serial No. 320,139.

My invention relates tolamps of the type particularly adapted for street lightin in which it is important that'the position of the lamp filament shall be accurately placed in order to insure proper light distribution.

. Lamps of this type are provided with light distributing elements such as globes and refractors.

Among the objects of my invention are to provide a lamp in which elements for sighting purposes are located on the light distributing elements on opposite sides of the light source, which sighting elements are visible each from the opposite side of the lamp, through transparent sections on the light distributing elements whereby the filament of the light source may be referred to the sightingelements for properly alining the filament with respect to the light distributing elements.

The invention will be readily understood from the following specification and claims, reference being had to the accompanying drawings, in which Fig. 1 shows a lamp with a globe and with'refractors in elevation and partly in section embodying the features of my invention; Fig. 2 is a section of the same device in side View showing how the connections are made between the socket in the fixture and the terminal; Fig. 3 is an enlarged view of the refractors of Fig. 1, in which figure the refractor is shown in front elevation and partly in section; Fig. 4 isa portion of the refractor of Fig. 3, enlarged and showing the sighting means; Fig. 5 shows another form of lamp in front elevation, with the globe omitted and with the refractors inverted, having the features of the invention;

Fig. 6 isa portion of the refractor of Fig. 5 enlarged and showing the sighting elements; Fig. 7 is an enlarged side View of the refractor of Fig. 5 partly in section.

Referring more in detail to the drawings it will be seen that the lamp in Fig. 1 comprises a casing 2 of insulating material, such as porcelain or other ceramic material. The lamp is provided with 'an iron cap element 3 to which the casing.2 is suitably secured as for example by means of screws which are threaded in the cap 3 and which project into depressions or cavities in the casing 2. To the lower part of the casing there are secured in any suitable manner the refractor elements 4 and 5 located one inside of the other. Also independently secured to the lower face of the casing is the globe ti which is provided with a holder Tim the form of a band secured around the neck of the globe. This holder is provided.

on one side with a hook 8 which is hinged to the support 9, the latter being anchored in the lower face of the casing 2. On the opposite side of the holder there is provided a latch element 10 which serves as a hand element to draw the globe into position as shown in Fig. 1, whereupon the lever 10 is latched over the hookedportion of the latch element 11. With this form of fixture it is essential that the lamp 12 should be properly adjusted with respect to the refractor. In order that this may be accomplished readily without having to open the globe the socket 13 is secured to a block 14 which is provided with a threaded 'side of the hood in any suitable manner, as

for example by means of screws 18. The screw 16 is provided near its lower end'with a gear Wheel 19. In engagement with gear wheel 19, there is a second gear wheel 20 which is mounted on a shaft 21 that has a hearing in the member 17. This shaft extends through the wall of the hood and terminates in a polygonal terminal element 22 adapted to be engaged by a suitable hollow key. The arrangement is such that by rotating the shaft 21 the screw 16 is rotated. It rotated in one direction, the block 14, and therefore the socket 13, will be raised. On the other hand, if rotated in the reverse direction the socket 13 will be lowered. By this means the lamp 12 may be readily adjusted from the outside.

In order to effectively determine the proper height of the lamp filament, I provide sightrefraotor shown in igs. 1 and 3 the inner and outer reiraetor elements 4 and 5 are each provided with clear portions such as the portions 32 and 33 in alignment with each other.

. These portions may be circular, square or of any suitable shape provided, a view of the filament of the lamp may be had. On the opposite side of the refractor there are provided two similar portions 34 and 35 diametrically opposite the portions 32 and 33. The outer portions 32 and 34 are provided with suitable markings such as, for example, horizontal ridges or marks 36. In order that the sighting may be done through the globe, the latter isprovided with clear windows 38 and 39 on opposite sides of the globe and in alignment withthe clear portions 32, 33, 34, and 35. By aligning the filament of the lamp 12yvith any one of the horizontal markings on the portion 32 and with a corresponding horizontal marking on the portion 34, theposition of the fila- Inent may be adjusted with considerable prec1s1on.

The arrangement of the sighting means in Figs. 5, 6 and 7 is substantially the same as in Figs. 1, 2 and 3, each of the refractor elements 23 and 24 being provided with clear portions 25, 26, 27 and 28, all of which are in alignment. In these figures the outside portions are also provided with the sighting marks 29 similar to the ridges 36, Fig. 3. The main difference between the units 1 and 5 is that there is no globe outside the refractor and consequently there are no windows corresponding to the globe windows 38 and 39, Fig. 1, and that this refractor is of the inverted type.

It will be understood that while I have elected to illustrate my invention in connection with the specific form of apparatus shown in the drawings, I do not care to be limited to this particular form of apparatus, inasmuch as I contemplate variation and modifications suggested by the disclosure which do not depart from the spirit of the invention nor from the scope of the claims contained herein.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a lighting unit, in combination, a light source and light diffusing elements comprising a pair of refractors and a globe, a hood for supporting said elements in proper relation, said globe enclosing said refractors, one of said refractors being located inside the other and said light source being located under said refractors, transparent means on each of said light diffusing elements on both sides of the light source, all of said transparent means being located in alinement along a ginen axis, one of said transparent means on each side of the light source being provided with sighting means thereon, the sighting meanson each side of the light source being visible from the opposite side of the light source and from the outside of the unit through said transparent means along said line whereby the filament of the light source may be properly alined with res ectto the sighting means on both sides 0 the light source.

. 2. In a lightin unit, in combination, an electric lamp and light diffusing elements c'omprising a pair of refractors, a hood for supporting said elements in proper relation, one of said refractors being located inside the other and both over the lamp, transparent means on each of said light diffusing elements on both sides of the lamp, all of said transparent means being located in alinement along a given axis extending through the lamp, one of said transparent means on each side of the lamp being provided with sighting means thereon, thesightin means on each side of the lamp being visib e from the opposite side of the lamp throu h the said transparent means whereby the filament of the lamp may be properly alined with respect to the sighting means on both sides of the light source.

3. In a lighting unit, in combination, a light source, light diffusing elements comprising a refractor and a globe, a hood for supporting said elements in proper relation, said globe enclosing said refractor and said light source being located under said refractor, transparent means on each of said light diffusing elements on both sides of the light source, all of said transparent means being located in alignment along a given axis, one of said transparent means on each side of the light source being provided with sightside of the light source being visible from the opposite side of the light source and from the outside of the unit through said transparent means along said line, whereby the filament of the light source may be properly aligned with respect to the sighting means on both sides of the light source.

In witness whereof, I have hereunto set 'my hand this 15th day of November, 1928.

GROMWELL A. B. HALVORSON.

111g means thereon, the sighting means on each 

